A new Microsoft 365 application was installed

Goal

Detect when a new Microsoft 365 app is installed as a means of establishing persistence.

Strategy

Monitor Microsoft 365 audit logs to look for events with an @evt.name value of Add application. and event @evt.outcome of Success.

Triage and response

  1. Determine if the user {{@usr.email}} intended to install {{@ObjectId}}.
  2. If {{@usr.email}} is not responsible for installing {{@ObjectId}}, investigate {{@usr.email}} for anomalous activity. If necessary, initiate your company’s incident response (IR) process.